Opened 3 years ago

Last modified 2 weeks ago

#358 new defect

DEFMACRO incorrect (un)dead-code-elimination in

Reported by: mevenson Owned by:
Priority: major Milestone: 1.6.0
Component: interpreter Version: 1.4.0-dev
Keywords: Cc:
Parent Tickets:

Description

Douglas Katzman notes in http://article.gmane.org/gmane.lisp.armedbear.devel/3171:

;; In the test below, COMPUTE-INSIDES should be called by EXAMP-FAIL

java -jar abcl-bin-1.3.0/abcl.jar
...
CL-USER(1): (defmacro ultra-fancy-macro (&optional (x 'compute-insides))
                    (list 'cons ''loop (list x)))
ULTRA-FANCY-MACRO

CL-USER(2): (defun examp-fail (directives)
                   (labels ((compute-insides () '((here-are-the-guts)))
                               (compute-loop () (ultra-fancy-macro)))
                    (compute-loop)))
; Note: deleting unused local function LABELS COMPUTE-INSIDES
EXAMP-FAIL

CL-USER(3): (examp-fail nil) ; just checking.. maybe the Note was wrong?
(examp-fail nil)
#<THREAD "interpreter" {652D03DC}>: 
Debugger invoked on condition of type UNDEFINED-FUNCTION
 The function COMPUTE-INSIDES is undefined.
Restarts:
...
3: TOP-LEVEL    Return to top level.
[1] CL-USER(4): 3

CL-USER(5): (defun examp-works (directives)
                    (labels ((compute-insides () '((here-are-the-guts)))
                                (compute-loop () (ultra-fancy-macro)))
                     #'compute-insides ; spuriously reference it
                     (compute-loop)))
EXAMP-WORKS

CL-USER(6): (examp-works nil)
(LOOP (HERE-ARE-THE-GUTS))

Without a statically observable use of compute-insides it is considered unused.
Macros have expanded *before* deciding that.
It is clear that the macro expands correctly based on 'examp-works'

Subtickets (add)

Change History (2)

comment:1 Changed 9 months ago by mevenson

  • Milestone changed from 1.4.0 to 1.5.0

Ticket retargeted after milestone closed

comment:2 Changed 2 weeks ago by mevenson

  • Milestone changed from 1.5.0 to 1.6.0

Ticket retargeted after milestone closed

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